There is a demand for the ability to monitor the charging status in the storage battery of a vehicle. After a number of cold starts, trips with small mileage or with use of energy demanding extra equipment in the vehicle, there is a risk that the effective output of the generator will no longer be sufficient to drive all equipment and simultaneously give enough energy for recharging the storage battery. Furthermore, an accumulator battery is successively aged, which means that over time it takes a longer time to recharge it and the total accumulator capacity is reduced. Power dissipation may also occur in the generator or other parts of the electrical system so that the output of the generator is reduced or a voltage drop occurs.
Having access to information about the charging status of the battery, the driver of the vehicle can be in a better position to avoid starting problems, e.g. by changing an old battery, by adjustment of the power consumption so that the battery receives proper charging or by additional recharging of a temporarily run-down battery.
Known means for determining the charging of a battery does not consider the age of the battery, and typically use rather deliberate and expensive sensor means for detection.